Located: North Eastern Brazil to Central Argentina.
Size: 5 feet tall
Incubation: 35 - 40 days
No. of Young: Up to 18 eggs
Lifespan: 15 - 20 years
Breeding: 5 to 7 hens to a cock. The male prepares
the nest. Females lay up to 18 eggs which the cock incubates and thereafter
rears the young on his own.
Food in wild: Adult - mainly grass, some insects
and small invertebrates. Young - only insects.
Food in zoo: Mazuri pellets, flaked maize, apples, brown
bread, lettuce, turkey rearer pellets.
Andy Smyth, Glasgow
The seven female and two male rheas have produced numerous eggs, and
both males - as is usual in ratites - have gone broody.
We pondered whether or not to remove some of the eggs, and with hindsight
perhaps we should have done. The two males have been trying to incubate
forty or fifty eggs. They have a nest in the middle of the paddock
amongst the long grass.
problem is that, with so many eggs, they are unable to cover them
all at one time. In consequence, eggs get chilled. During incubation,
these get rolled back into the nest and some other egg in turn gets
chilled. By the end of a lengthy incubation period most of the clutch
may have perished in this way - a recognised phenomenon amongst
poultry and waterfowl breeders. We werent desperate to breed
numerous rheas this year anyway, but regret not restricting the
numbers of eggs these males were attempting to cover.
Rheas are the true inhabitants of the South American grasslands
or pampas. Examples of pampas grass can be seen on the lawn, halfway
up the main drive just down from the Barbary sheep. Imported into
Britain on many occasions by landowners and collectors like the
Duke of Bedford for his Woburn estate, rheas were first bred in
Scotland during the nineteenth century. They are now considered
almost - though not quite - domesticated, with a white variation
being quite common.
Distribution in the wild is from north-eastern Brazil to central
Argentina. Although conspicuous to our eyes, on the pampas, crouched,
immobile, amongst the tussocky grass, they are almost invisible.
Then, when something alarms them, off they go, in typical, high-stepping
ostrich style, reaching speeds of 30 m.p.h., and zig-zagging this
way and that, often with wings outstretched and bending to one side,
then the other, at acute angles.
Their lifespan is 15-20 years, and we have always found them
trouble-free and very hardy, seemingly impervious to the coldest
temperatures. Our group of two males and five females are descended
from birds we first bred back in 1980 (at the bottom of the hill
where the llamas
are now kept). They are four years old. Each female lays from 15-20
eggs - one every second day - in May and June. These are gathered
together by the cock birds and incubated for about 35 days. In 1999
we made the mistake of not limiting the numbers of eggs each male
attempted to 'cover' so, one by one, each rolled out of the nest
for a period and was chilled. This year we intend to artificially
incubate some, letting the fathers incubate smaller clutches of
15-18 eggs. Some of last year's eggs have been left our for you
to look at.
Chicks when they hatch are insectivorous, before moving on
to short grass, shoots and invertebrates of all sorts. The father
carries out all the incubation and rearing. 'Surplus' eggs can be
artificially incubated, but great care has to be taken with the
chicks, as sometimes leg problems can result if the diet is not
precisely correct. Adults in the wild feed on all sorts of vegetation
supplemented whenever possible with all sorts of small creatures.
Male birds have darker, blacker necks and are a little taller. One
of the female birds appears paler than the others, and we suspect
this is some form of dilute such as a 'Silver' or a 'Cinnamon'
variant in other bird species.